The present invention relates to a radio communication apparatus including a power supply device of the type using a solar battery and, more particularly, to a power supply device capable of operating over a long period of time with a relatively small capacity.
In a radio communication system such as a single-channel-Per-carrier (SCPC) communication system, a radio communication apparatus whose capacity is relatively small is implemented with a power supply device of the type using a solar battery for ease of maintenance. It has been customary to construct a solar battery-type power supply device such that the voltage of a solar battery is monitored and, when it is lowered to a predetermined level, the power supply is interrupted so as to protect the battery and insure its long service life. Further, it is a common practice to use a solar battery having a capacity which is ten times greater than the maximum capacity used, providing for nighttime and rainy weather. A drawback with such a prior art device is that upon the drop of voltage beyond the predetermined level all the communications are shut off, although the solar battery may be protected. In addition, the capacity which is approximately ten times greater than the maximum capacity used as stated above is undesirable from the cost standpoint.